Multiple engagement latch



SPt 4, 17945- .L R. BURBRIDGE 2,384,276

MULTIPLE ENGAGEMENT LATCH Filed sept. 2'7, 1943` 2 sheets-sheetlv ArroRNEYS Sept' 4, 1945- J. R. BURBRIDGE 2,384,276

MULTIPLE ENGAGEMENT LATCH Filed Sept. 27, 1945 2 Sheets-Sheet 2 FIGB?? FIGB@ M @M/#df i INVENTOR ATTORNEYS Patenteci Sept. 4, 1945 fre-D Siri-fr fli:s @PATENT io/Fierce MULTIPLEENGAGEMETLATGH @John eR.f Burbridge, Kenosha, `eWas.iassigner of 1 one #half lto; Stanley -D. aEilenbvergex-,a-Kenosha,

`Willis. @ApplieationlSeptemher 27; y19435S5eriaIfNo.#50415010 A11i Claims. (Cl.292-..-:254

VlvThis 'inventiorrrelates tcfan improved -'1atching Alfurther `bbjecteofwmy invention is tovpro'vide *device for-nse-ondoorsand4 in particular for-use I'atlatehingdevice-'Which-may\ be released'xwith on suchdoors asareusedon vmoving conveyanes, awrninimun'rof`r effort.

*as-'forfexampleonrailroa'd' cars-and automobiles "'A-s'till"further-object -of my invention is to -thearchingdeviee.k There are-methedeavaiiable lat'ehing devieeselieine relatively e heavy4 spring Which'areoften adjusted to exert sufficient pites- "CombineallY'J0l`*1i"0f"iii'le' foregoingv Objects hill e f-'sureeagainstthe doorr tao-prevent -suchrattling, `"Single li'fehing device Additional Objects -Wi11 "-'known and luscrlqoiiorto'this'V inventiony such 15 nivli'efiyf'llly illV-eii'lOlPCOlllDriSeSw multiple devices have, in-generar been uneatis-facteryver latehing pawl Wheref-eaeH-latehine--pawlisfprexex-pensive toman'ufaeture; orbdth. *The present decree-'bv'- a4 separate-'fSpring,said` multiple-vwl invention discloses a device for maintaininginti- Y "ellgagirlg' a* multiple' ellgegellleililV` Strikillgplete 'amate eontaetbetweenthe-latching pawlandthe `*in**auch3"'H1aI1I1el`'fleiPpOSlfive engagement iS striking 'plate, Without resorting `to e excessive 20faorded'foranydegree ofy closure oi'` the doorn A'springfpiessure in the'doorchecknormallyused "The deSiglVOf kl'fhe *engagemeili 'DeWiS and* the .Atofinsure `-ensure 0fV afdOOr, L'Inl addition to vthe 'multi'plestrikingplate'issuch-that fora-condivimprovedmethod of maintaining intim-ate-con Atiorrwheretheldoor is elosedsuiciently to afford tact'-betweer1f the -latching' pawland therstriking initial engagement, ally-furthermevemellt -O the Wlatei'myeimprovedl-latfohing'idevice-aisoe'ineludes 251@0013from'viblaiion?f01`"'eXamp1ef"Wiu'result in `a' new e and' never `lat-ch Y .release which may be 1- additionalengagement andv thus-provide atighter l operatdiwthia minimum Ofappled force. '-closurethan Was-'initially afforded.

.It is Wu knownethatfnumemuslatchmgtd -This'inventionWil11bebestunderstood'incon- 1 Vices new,m common use especiuy von conve sidera-tion olthef followingf detailed description, *aneesislehe as railroad cars;make'usepfheavyniniview 0fthef-aeeemparlyillg'drewillgs fermillg e; Springpressure v011.100th`:weldoorclosuredevice a part of the application. Nevertheless, yit is unandron the .latching paWL wfmslav Serious dis f derstood 'thatthe inventionis not conned to the advantage in that considerable ""foree" must Abe i-diSClOSU-Iei beiliSuSCePi'libie.SOSllCh Changes'alld applied -to' the latch release-handle' in-"order to ""mdcations'as"dene"n0 material departure n release 'thenlatching pawliandin addition ,con .35-from='the salient Lfeatures of the "invention `as #siderablei lforce must loe Yappliedeto open thedoor "expressed in' 'the' appended :Claimsagainst thedoor closuretdevicespring'pressure. In the drawings: Thisheavy spring'pressure' sxused torinsure rm Figura 1 "is 'a' ODCTOSSL SeCiiOn View 'Showing closureof the'door'and'toiinsure intimate con- :thel'multiple paw1"'secti0n`0f my latchin'devce tactbetween the latchingpawl and the "striking Aommmfted'fin':thev'door 'jamb Or'framef and the plate and, `whim Suck heavy ,Spngmressure vis -m11lt1-ple engagement -strikingplateg together with veffective forthe` intended'purpose;iitffers a ser- 'fthef"paw1.releasvmechanismf mounted Orl the iousrdisadvantage' in that' considerable 'strength i;dooriithis"viali/*beingfai a"C0I1dii5i0ll Where the 'is-required" to fopen *theidoon 'which' results in 1100i is`nat`eembieteiy` Closed- `considerableineonvenierime;whichie particuiamy f 4 A-*erief1re'-2*ise tepeross section" view similar to -so`^whenithe person 4desiringto open'theL door is ihair'shewli'ibyaigure' 1; thrsvew. representing a handicapped Withpackages. reoriditionmwhere the door istightly closed.

jMyinvention'iedesigned to. provide rm 'closure "ilFigu-reirrepresents a iep Cross section View :of a "doorwithout -resoitii[1, gto excessive uspring "SiiiiilaliiFigllre lfOl e'COIidiiOil'Whereihe lJaWl 1 pressure'-emd5150\Jyflgrovidg-fOr-easyopeningv 50 release-mechanisnris in the operated position,

of adoor' without exerting considerable force. SHOWillgihe .DaWiS releaSed vfind the dOOr .partly A principal object of my invention is to provide Opelli a' latching device which 'i willi provide intimate "Figill'e 4i`a'phallt0m Side View ShOWillgl-eiail :contact betweenithel'atching pawl and thestrik- Ofi-the pawl`A release mechanism.. img; plate. 1 i 5 *Figure 5 is affront view ofthe multiple eng-agement striking plate with the pawl release mechanism in the nonoperated position.

Figure 6 is a top cross section view of the multiple striking plate showing the multiple Pawls in the engaged position with the pawl release mechanism in the non-operated position.

Figure 7 is a front view of the multiple striking plate showing the pawl release mechanism in the operated position.

Figure 8 is a top cross section view of the multiple striking plate showing the multiple pawlin the operated position, with the multiple `pawls disengaged. Y

Referring now in particular to' Figure l,v a section of the door jamb or frame is represented'by I and the latch mounting case by 2. The engagement pawls are represented by 3and 5, where 5 is the primary engagement pawl and 3 the secondary engagement pawl. The pawl springs are represented by 6 and 'I where 6 is the primary pawl spring and 'I the Secondary pawl spring. The latch mounting screws are represented by 4 and the door stop by 8. A sectional view of the door is represented by 9 where I2 represents themultiple engagement strikingsplate, the engagement teeth being represented by I3, I4, I9 and 20, four such engagement teeth beingshown in the drawing, it being understood that any desired number of such engagement teeth may be used. The

pawl release dog is representedby I5, the pawl release operatingcam by I8, the pawl release dog fulcrum by I6, and the pawl release return springs by I'I. The striking plate mounting screws are represented Vby II, and the pawl release operating handle by Il).Y Y

Figure 1 represents a condition where door 3 is not completely closed, the space 22 between door 9 and door stop V8 being representativev of a condition where the door 9 is almost, but not completely, in contact with the door stop 8.l It is Well known that such a ycondltionwill allow the door to rattle, where the usual type of sing engagement latch ishused. Y. Y j

In the partly closed top cross sectlonview of Figure l, actual engagement is between primary pawl 5 and engagement tooth- 20. Secondary engagement pawl 3 is shownpartly depressed and, while secondary pawl V3 is not actually engaged, it acts to strengthen the engagement made by primary pawl 5. Y A

Referring now in particular to Figure 2 which is identical to Figure l, except that space 22 in Figure 1 has now been eliminated by fcomplete closure of the door, complete closure being represented by engagement ofsecondary pawl 3fwith latching tooth I9. y Y,

The entire latching mechanism as represented, by Figures 1 and 2, is so designed as toaiord eight engagement positions. The number of engage;

ment positions alorded will always be the product of the number of pawls used and the `number of teeth in the multiple engagement striking plate. For purposesof example, the total number of engagements represented is eight, it being a condition where three pawls were used in con-A f junction with a ve'tooth striking plate, a total of iifteen engagements would be ciered, as compared to the usual type of latching devicefrnany of which depend'on asingle engagement latch.v

A practical resultof'this vdesign issth'at .awslighti movement of the door, from any cause, will result in tighter closure of the door. For example, in Figures 1 and 2, where a total of eight engagements is shown, a movement of 1/8 of the total engagement distance will afford a further engagement. A further practical result obtained by the use of my latching device is that positive engagement is always afforded, irrespective of alinement of the door With'the latching device.

It is commonly known that with'the usual type of latching device misalinement of the door results in a condition Where the latching pawl does not engage the striking plate, and this is usually so irrespective of the form of misalinement. For example, in one common form of latching device where the pawl engagement is made through the striking plate, a slight sag in the door will result in a condition where the pawl strikes the solid part of the striking plate and no engagement is possible.

A further diiculty often encountered in this type of latching device is a condition where the alinement between the door and the door stop is such that the door cannot be closed suiliciently to allow the engagement pawl to project through the striking plate, and this also results in a condition` Where no engagement is possible. Diillculties of the type cited above cannot occur with my improved latching device. vDue to the multiple engagement feature, exact alinement between the door and the door stop is of little importance. This is also true in respect to vertical alinement, as the boundaries of the striking plate are not absolutely dened, and engagement will be aiorded for any condition where the pawl meets with the striking plate so that for any condition where a door will close atall positive engagement will be afforded.

Referring now in'particular to Figure 3, the pawl release mechanism is shown in the operated position where handle I0 has been turned Vat right angles to the release position represented in Figures l and 2. Cam I8 is formed as an integral part of handle I0 and in the operated position cam I8 exerts pressure against movable dog I5, causing said movable dog I5 to project through an opening provided in striking plate I2, and so causingsaid movable dog to exert pressure against latching pawls 3 and 5, so that said pawls are no longer engaged with any of the latching teeth of the striking plate. The space 23 in Figure 3 represents the door in a. partly opened position and with the pawl release mechanism in the position shown in Figure 3 the door may b e completely opened and, uponrelease of handle I0, pawl release dog I5 will be returned to the non-operated position by springs I1.

The construction of this pawl release mechanism willi be further clarified from a consideration of Figure 4, which is a side phantom view clearly showing the relationship-between handle I0, cam I8, pawl release dog I5, release dog fulcrum I6, striking platel I2 and'secondary pawl 3.

The operation of this' pawl release mechanism will be further clarified in view of Figures 5 and 6, where Figure 5 represents a front view of striking plate I2 clearly showing openingZI provided in striking plate I2, with pawl re1eased0g .I5 in the non-operated position, the desigrfbeing such that in the non-operated position, pawl release dog I5 is ilush withjor'below; the surfacefof .striking platen-f Y,

Figure 6 is av top cross section view representing the same Ycondition as that represented, by Figure 5 and 'clearly showing the engagement of secondary latching pawl 3 with latching tooth assenze 3 plete-l2; Y *l eaten-entitheclosure having a series of geltdlfie ve'vvof4 the feregoingdescrptiomfi isapi:i` sa-idfI pawls Yhav-irrtv 'cooperatigflshould s? that' such a latching device inaylalsobe .used'f'on any type of door Where polsitivelatchi'ng isan a' vantage. For example, suon a Iatching'fidevice may ybe manufactured economically'f'forusejon an v"adjacent -netcl'tiadholdltlieclosure'geins doersY 0f the 'type' usuallyfemployed in dvvellifnes movement;v and'"rneansoriitnel-oiosure adaptedl and otherebuldingsand, Whilefsuchfdoorsgarenott L10' when operated t0 foreefthelbevele enelsofthe'fr nirnally subject to vibrationrfin'yimproveiillat Ult-'of Said not h sir "tw ing device-offers advantages not-'found'lfn"previ @pgn wird@ ous devices of the class described. Y Y llatclfing arrangement:'oralclosue mov In the drawings, the striking plate-and pavvl y ablyv mounted'inalframefconprsing y i release mechanism is shown'rnount'ed in thedo'r r @tong-"amis slifdablvl rriOunt-Sd*in"thel fral with the cor-"operating latchin'g'-v pawls'jmounted 1n'A the door jambor frame, it being.-underst()od taiaty this arrangement mayy beY "reinersed f" desired.: With reversed mounting; ijje;, mounting opposite toiftliat shown in the drawings) the pawl release handle would appear onv the dorframeorugas--v ing rather thanV on the door and',V foreertainv pu'ref poses', this-reverse 'mounting offers deniteadj-j'j vantages; yit being understood that for'the pui#y poses of `this invention'itpisoffno material iin-i' pnjrtaricewhich4 type of mounting isfernploye'd Theabove examplesjareforthe'purposeoi a'dapte'dtof t outwardlyof theidcat lustrat-ingA'` some ofth'e methods an'd'means ,y1 operating the g jfovrm causing lsaid' dog which the broad purposes ofjthe linventionmayY gage* and' rno `the beveled ends jofthe ing nog inox/,amy 'mountedinane-jews' strictivelin any manner; lOther modicationsf .opened 1 andalternatives Will-occur to those skilled ingthefjf artfwithout departing 'from the' vscopev of the inl-Ai vent'n as defined by the'ffollovving claims:v

I'claim:

frame and adapted `to lbevengage l. A latching arrangement for a closure movl y ,y I I e. @e ably mountedin a fa'rnecornprising a pair of edge "of Vtli'e'door'when `'said'dooris moved topawls slidably mounted in the frame, a catch on wards closing position, springs projecting the the closure having a series of motches, a spring beveled ends 0f the pawls outwardly from the urging both pawls towards the catch, a second 70 frame, a catch on the free edge of the door and spring urging one pawl toward the catch indeprovided With notches adapted to be engaged sucpendently of the rst spring, the outer ends of cessively by the beveled ends of the pawls for the pawls being beveled so that both beveled holding the door against movement during-proends of said pawls will enter a single notch, or gressive stages ofclosing, means on the door and one beveled end of one paWl will enter said notch 75 adapted to be moved outwardly therefrom for 

